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Articles 301 - 330 of 694

Full-Text Articles in Physical Sciences and Mathematics

Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan Jan 2013

Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan

Dissertations and Theses

Organic aerosols have significant effects on human health, air quality and climate. Secondary organic aerosols (SOA) are produced by the oxidation of primary-volatile organic compounds (VOC). For example, α-pinene reacts with oxidants such as hydroxyl radical (OH), ozone (O3), and nitrate radical (NO3), accounting for a significant portion of total organic aerosol in the atmosphere. Experimental studies have shown that the oxidation process between α-pinene and ozone has the most significant impact in the formation of SOA (Hoffmann et al., 1997). Most of the models used to predict SOA formation, however, are limited in that they …


Beijing’S Water Crisis: A Historical Analysis Of Beijing’S Waterways Using Geographic Information Systems, Rebecca Tisherman Jan 2013

Beijing’S Water Crisis: A Historical Analysis Of Beijing’S Waterways Using Geographic Information Systems, Rebecca Tisherman

Environmental Studies Honors Papers

Beijing has a complex system of waterways inside the city of 20 million people, while the rivers just outside of the city run dry most of the year. Geographic Information Systems was used to analyze the historical changes of the waterways, geo-cover, precipitation, and other factors that have affected the water supply to the city. The manmade canals in the city expanded with urbanization until 1983 when there were canals in every corner of the city. The water became too polluted for human use, so canals were slowly converted to culverts. Groundwater was depleted over time as well, so the …


A Highly Efficient Tio2-Xcx Nano-Heterojunction Photocatalyst For Visible-Light Induced Antibacterial Applications, Vinodkumar Etacheri, Michael Seery, Stephen Hinder, Georg Michlits, Suresh Pillai Jan 2013

A Highly Efficient Tio2-Xcx Nano-Heterojunction Photocatalyst For Visible-Light Induced Antibacterial Applications, Vinodkumar Etacheri, Michael Seery, Stephen Hinder, Georg Michlits, Suresh Pillai

Articles

Visible-light-induced antibacterial activity of carbon-doped anatase-brookite titania nano-heterojunction photocatalysts are reported for the first time. These heterostructures were prepared using a novel low temperature (100 °C) non-hydrothermal low power microwave (300 W) assisted method. Formation of interband C 2p states was found to be responsible for the band gap narrowing of the carbon doped heterojunctions. The most active photocatalyst obtained after 60 minutes of microwave irradiation exhibits a 2-fold higher visible-light induced photocatalytic activity in contrast to the standard commercial photocatalyst Evonik-Degussa P-25. Staphylococcus aureus inactivation rate constant for carbon-doped nano-heterojunctions and the standard photocatalyst was 0.0023 and -0.0081 min …


Short-Term Denitrification In The Metalimnion Of A Eutrophic Reservoir, Aki Kogo, Erin M. Grantz, Thad Scott Jan 2013

Short-Term Denitrification In The Metalimnion Of A Eutrophic Reservoir, Aki Kogo, Erin M. Grantz, Thad Scott

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Denitrification in metalimnetic water was examined under different conditions to determine how addition of nitrate (NO3 -) and particulate carbon (PC), aeration, and concentrations of nitrate affect denitrification. In the first experiment, water samples from a metalimnion were treated with different combinations of NO3 - and PC. Changes in excess N2 -N concentration for 10 days were measured using membrane inlet mass spectrometry (MIMS). The second experiment used the same treatments as the first experiment after aeration of water. Besides excess N2 -N concentrations, O2 concentrations were measured for 16 days. The third experiment examined how different initial concentrations of …


Environmentally Green Synthesis Of Thioformamide Derivatives, Ali Ramazani, Sang Woo Joo, Fatemeh Zeinali Nasrabadi Jan 2013

Environmentally Green Synthesis Of Thioformamide Derivatives, Ali Ramazani, Sang Woo Joo, Fatemeh Zeinali Nasrabadi

Turkish Journal of Chemistry

Reactions of isocyanides with thioacids in water proceeded smoothly at room temperature and in neutral conditions to afford thioformylamide and thioformamide derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed.


Palladium-Edta And Palladium-Edteh_4 Catalyzed Heck Coupling Reactions In Pure Water, Süleyman Gülcemal, Beki̇r Çeti̇nkaya Jan 2013

Palladium-Edta And Palladium-Edteh_4 Catalyzed Heck Coupling Reactions In Pure Water, Süleyman Gülcemal, Beki̇r Çeti̇nkaya

Turkish Journal of Chemistry

Palladium-catalyzed Heck coupling reactions of styrene with bromoarene derivatives are carried out under aerobic conditions in water using water-soluble N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine (EdteH_4) and ethylenediaminetetraacetic acid disodium salt (Na_2EDTA) as ligands. The effect of different bases, catalyst loading, and additives is also monitored. The olefination of bromoarenes with styrene affords the desired products in high yields. The Na_2PdCl_4-Na_2EDTA precatalyst system is also used for the preparative scale (50.0 mmol) synthesis of 4-acetyl-trans-stilbene and 4-styrylbenzaldehyde without a noticeable decrease in the activity. Recycling studies on the Na_2PdCl_4 - Na_2EDTA precatalyst system are also tested in the coupling of 4-bromoacetophenone with styrene.


Determination Of Zineb In Tap Water And Tomato Samples By Adsorptive Catalytic Stripping Voltammetry, Özlem Karakoç, Nuri̇ Naki̇boğlu Jan 2013

Determination Of Zineb In Tap Water And Tomato Samples By Adsorptive Catalytic Stripping Voltammetry, Özlem Karakoç, Nuri̇ Naki̇boğlu

Turkish Journal of Chemistry

This paper describes a sensitive and accurate adsorptive catalytic stripping voltammetric method for the determination of zineb (zinc ethylene-bis- dithiocarbamate) in tap water and tomato samples. The method is based on the reduction of adsorbed zineb at a hanging mercury drop electrode following its catalytic oxidation using peroxydisulfate as an oxidizing reagent. Chemical and instrumental parameters of the process were optimized. The catalytic mechanism of the reduction of zineb is discussed as well. The limits of detection (3 s) and quantification (10 s) and linear range of the method for accumulation time of 60 s were calculated as 8.1 nM, …


Hydraulic Fracturing And Water Use In Dallas, Texas, Sarah Yates Jan 2013

Hydraulic Fracturing And Water Use In Dallas, Texas, Sarah Yates

LSU Master's Theses

Dallas, Texas is located in North Texas and sits above the eastern portion of the Barnett Shale natural gas formation. Hydraulic fracturing, or “fracking”, was introduced to the region as a means to access previously inaccessible natural gas within the formation. This fracking concerns many because it requires large amounts of fresh water, an average of over 4 million gallons per well within Dallas Water Utilities’ service area. This thesis examines whether water use for fracking will have a negative effect on the water supply for the city of Dallas and its wholesale water customer cities. The water is typically …


Groundwater-Level Changes In Nebraska - Spring 2012 To Spring 2013, A. Young, M. E. Burbach, L. M. Howard Jan 2013

Groundwater-Level Changes In Nebraska - Spring 2012 To Spring 2013, A. Young, M. E. Burbach, L. M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Background Reading: Department Of The Interior, 2013 Departmental Overview, United States. Department Of The Interior, Ken Salazar Dec 2012

Background Reading: Department Of The Interior, 2013 Departmental Overview, United States. Department Of The Interior, Ken Salazar

The Future of Natural Resources Policy (December 6)

18 pages (DO-5 through DO-22).

"Background Reading"

The Future of Natural Resources Policy: This forum will provide a post-election perspective on some of the challenges and opportunities that natural resources, public lands, and energy policymakers in Washington are likely to face in the next four years. An expert panel will discuss the dynamics in the Department of the Interior, the Department of Agriculture, and Congress, and how their evolving policies are likely to affect Colorado in the coming years.


Slides: Colorado Law: Protecting Water Quantity And Quality, Alan E. Curtis Nov 2012

Slides: Colorado Law: Protecting Water Quantity And Quality, Alan E. Curtis

Monitoring and Protecting Groundwater During Oil and Gas Development (November 26)

Presenter: Alan E. Curtis, White & Jankowski, LLP

23 slides


Sustainable Water Management On Brownfields Sites, Ryan Fenwick, New England Environmental Finance Center Oct 2012

Sustainable Water Management On Brownfields Sites, Ryan Fenwick, New England Environmental Finance Center

Sustainable Communities Capacity Building

This practice guide was developed by the Environmental Finance Center Network (EFCN) through the Capacity Building for Sustainable Communities program funded by the US Department of Housing and Urban Development and the US Environmental Protection Agency. Through a cooperative agreement with HUD, EFCN is providing capacity building and technical assistance to recipients of grants from the federal Partnership for Sustainable Communities, an interagency collaboration that aims to help towns, cities, and regions develop in more economically, environmentally, and socially sustainable ways.


Drinking Water Resource Directory, New England Environmental Finance Center Oct 2012

Drinking Water Resource Directory, New England Environmental Finance Center

Sustainable Communities Capacity Building

This document is intended to help local and regional planning agencies, and their constituent water utilities, integrate drinking water infrastructure planning and investments into plans for sustainable development. Resources listed here provide guidance on making land use decisions that protect water resources, setting adequate and sustainable drinking water rates, controlling water loss, funding water infrastructure projects, and managing water utilities.

The directory was developed by the Environmental Finance Center Network through the Capacity Building for Sustainable Communities program funded by the U.S. Department of Housing and Urban Development and the Environmental Protection Agency. Through this program, EFCN is providing capacity …


Slides: Impacts Of Energy Deficits In Cooking, Illumination, Water, Sanitation, And Motive Power, Paul S. Chinowsky Sep 2012

Slides: Impacts Of Energy Deficits In Cooking, Illumination, Water, Sanitation, And Motive Power, Paul S. Chinowsky

2012 Energy Justice Conference and Technology Exposition (September 17-18)

Presenter: Dr. Paul Chinowsky, Director, Mortenson Center in Engineering for Developing Communities; Professor, University of Colorado

25 slides


A Review On The Visible Light Active Titanium Dioxide Photocatalysts For Environmental Applications, Miguel Pelaez, Nicholas Nolan, Suresh Pillai, Michael Seery, Polycarpos Falaras, Athanassios G. Kontos, Patrick S.M. Dunlop, Jeremy W.J. Hamiltone, J. Anthony Byrne, Kevin O’Shea, Mohammad H. Entezari, Dionysios D. Dionysiou Aug 2012

A Review On The Visible Light Active Titanium Dioxide Photocatalysts For Environmental Applications, Miguel Pelaez, Nicholas Nolan, Suresh Pillai, Michael Seery, Polycarpos Falaras, Athanassios G. Kontos, Patrick S.M. Dunlop, Jeremy W.J. Hamiltone, J. Anthony Byrne, Kevin O’Shea, Mohammad H. Entezari, Dionysios D. Dionysiou

Articles

Development of visible light active (VLA) titania photocatalysts

Fujishima and Honda (1972) demonstrated the potential of titanium dioxide (TiO 2) semiconductor mate-rials to split water into hydrogen and oxygen in a photo-electrochemical cell. Their work triggered the development of semiconductor photocatalysis for a wide range of environmental and energy applica-tions. One of the most significant scientific and commercial advances to date has been the development of visible light active (VLA) TiO2 photocatalytic materials. In this review, a background on TiO2 struc-ture, properties and electronic properties in photocatalysis is presented. The development of different strategies to modify TiO2 for the utilization …


Theoretical Approaches To The Characterization Of Water, Aqueous Interfaces, And Improved Sampling Of Protein Conformational Changes, Alexis J. Lee Aug 2012

Theoretical Approaches To The Characterization Of Water, Aqueous Interfaces, And Improved Sampling Of Protein Conformational Changes, Alexis J. Lee

LSU New Orleans Theses and Dissertations

Methods to advance the understanding of water and other aqueous systems are devel- oped. This work falls into three areas: The creation of better interaction potentials for water, improved methods for sampling configurational space, and the applications of these methods to understand systems of interest. Charge transfer has been shown by ab initio methods to be important in the water–water and water–ion interactions. A model for treating charge transfer in liquid water and aqueous systems is presented in this manuscript. The model is called Discrete Charge Transfer (DCT) and is based on the commonly-used TIP4P/2005 model, which represents the charge …


Synthesis Of 1,1-Dialkyhydrazines And Their Hydroxyl Radical Degradation In Aqueous Environments, Benjamin F. Strong Aug 2012

Synthesis Of 1,1-Dialkyhydrazines And Their Hydroxyl Radical Degradation In Aqueous Environments, Benjamin F. Strong

Masters Theses

Determination of hydroxyl radical rate constants are essential to ensure adequate degradation of contaminants in wastewater. Hydrazines are an important class of organic contaminants and are the focus of this research. Ten 1,1-dialkylhydrazines are synthesized by the zinc reduction of the corresponding N-nitrosamines. Their hydroxyl radical rate constants are determined using the linear accelerator at the Notre Dame Radiation Laboratory at pH 4, 7, and 10.

Their rate constants are found to depend on the protonation state of the molecule. At pH 4 the molecules are fully protonated and hydrogen atom abstraction is favored from the alkyl chains. At …


A Study Of Enhanced De-Chlorination And Bio-Remediation: Molasses Injections Into Groundwater, Brent Anderson Jun 2012

A Study Of Enhanced De-Chlorination And Bio-Remediation: Molasses Injections Into Groundwater, Brent Anderson

Natural Resources Management and Environmental Sciences

No abstract provided.


A Model To Relate Environmental Variation To Npdes Permit Violations At Thermoelectric Facilities On The Taunton River, Seth Delevan Sheldon Jun 2012

A Model To Relate Environmental Variation To Npdes Permit Violations At Thermoelectric Facilities On The Taunton River, Seth Delevan Sheldon

Graduate Doctoral Dissertations

Large thermoelectric facilities are issued permits to discharge high volume, high temperature effluents as part of the National Pollutant Discharge Elimination System (NPDES). Once-through cooled power plants are especially dependent on large quantities of cool water to operate. When ambient temperatures are high or streamflow is very low, power plant managers must reduce (i.e., "dial back") energy generation in order to avoid violating their NPDES permit limitations. Sudden dial-back can have human health impacts when electricity is no longer available to provide cooling or other vital services. A superior system of electricity and environmental management would reduce the probability of …


Dispersibility Of And Adsorption On Functionalized Carbon Nanotubes, Susana Addo Ntim May 2012

Dispersibility Of And Adsorption On Functionalized Carbon Nanotubes, Susana Addo Ntim

Dissertations

As the applications of carbon nanotubes (CNTs) proliferate, mass production and widespread use of these nanocarbons will continue to rise. While raw, unrefined, and hydrophobic carbon nanotubes tend to settle out of aqueous media/environments, water dispersible, functionalized CNTs (F-CNTs) will contaminate water resources and will also be highly bioavailable on exposure. Therefore, there is a need to develop an understanding of the fate of F-CNTs in aqueous media.

The colloidal behavior of aqueous dispersions of F-CNTs formed via carboxylation and polymer wrapping with polyvinyl pyrrolidone (PVP) is investigated. The presence of polymer on the nanotube surface provides steric stabilization, and …


Near Infrared-Red Models For The Remote Estimation Of Chlorophyll-Α Concentration In Optically Complex Turbid Productive Waters: From In Situ Measurements To Aerial Imagery, Daniela Gurlin May 2012

Near Infrared-Red Models For The Remote Estimation Of Chlorophyll-Α Concentration In Optically Complex Turbid Productive Waters: From In Situ Measurements To Aerial Imagery, Daniela Gurlin

School of Natural Resources: Dissertations, Theses, and Student Research

Today the water quality of many inland and coastal waters is compromised by cultural eutrophication in consequence of increased human agricultural and industrial activities and remote sensing is widely applied to monitor the trophic state of these waters. This study explores near infrared-red models for the remote estimation of chlorophyll-a concentration in turbid productive waters and compares several near infrared-red models developed within the last 35 years.

Three of these near infrared-red models were calibrated for a dataset with chlorophyll-a concentrations from 2.3 to 81.2 mg m-3 and validated for independent and statistically significantly different datasets with …


Measured Rates Of D2 Abstraction In H2o+ , D2 Substitution In H2do+ And Charge Transfer Of He2+ With Noble And Other Gases At <1ev, Chrysanthos Kyriakides May 2012

Measured Rates Of D2 Abstraction In H2o+ , D2 Substitution In H2do+ And Charge Transfer Of He2+ With Noble And Other Gases At <1ev, Chrysanthos Kyriakides

UNLV Theses, Dissertations, Professional Papers, and Capstones

Experimental determination of the rate coefficient values of deuterium abstraction in water ions and deuterium substitution in hydronium ions can improve the understanding of D/H in water at planetary atmospheres, cometary atmospheres, and interstellar medium. Using a cylindrical ion trap, (CIT) and time of flight (TOF) mass spectrometry, a number of measurements at energies below 1 eV have been performed. The deuterium abstraction rate coefficient in water ions, H2O+, and an upper limit for the hydrogen-deuterium substitution rate coefficient in monodeuterated hydronium ion, H2DO+, have been measured. Both the abstraction and substitution …


Water Infrastructure Challenges In Urbanizing Environments: A Case Study Of The 2009 Logan Canal Landslide, Kathryn Davis Henderson May 2012

Water Infrastructure Challenges In Urbanizing Environments: A Case Study Of The 2009 Logan Canal Landslide, Kathryn Davis Henderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In July, 2009 in Logan, Utah, a wet, steep hillside failed, leveling a home below and destroying an irrigation canal that ran along the hill. Three people were killed. The event and the resulting policy changes present an opportunity to uncover how frames, or social constructions, play into the policy development cycle. This case also uncovers the nuances involved when old infrastructure takes on new social meanings. Planners and policymakers that pay attention to frames and social dimensions may be able to minimize conflict.

The landslide received immediate media attention and spurred state legislation on canal safety. The event had …


Agenda: A Life Of Contributions For All Time: Symposium In Honor Of David H. Getches, University Of Colorado Boulder. School Of Law, University Of Colorado Law Review Apr 2012

Agenda: A Life Of Contributions For All Time: Symposium In Honor Of David H. Getches, University Of Colorado Boulder. School Of Law, University Of Colorado Law Review

A Life of Contributions for All Time: Symposium in Honor of David H. Getches (April 26-27)

On April 26-27, 2012, Colorado Law honored David H. Getches with a symposium to celebrate his life and legacy of trailblazing scholarship. “A Life of Contributions for All Time” featured a keynote address by Distinguished Professor Charles Wilkinson entitled, “Hero for the People, Hero for the Land and Water: Reflections on the Enduring Contributions of David Getches.” Top scholars in the fields of natural resources, water, and American Indian law reflected on Dean Getches’ contributions and their own insights into these fields, including Professor John Leshy, John Echohawk, Professor Carole Goldberg, Professor Joe Sax, Professor Rebecca Tsosie, Justice Greg Hobbs, …


Slides: Natural Gas: Game Changer Or Runner Left On Base? Working To Get It Right In Co!, Gary Graham Jan 2012

Slides: Natural Gas: Game Changer Or Runner Left On Base? Working To Get It Right In Co!, Gary Graham

Drawing the Blueprint for a Sustainable Natural Gas Future (January 18)

Presenter: Dr. Gary Graham, Director, Lands Program, Western Resource Advocates

21 slides


Technology Platform For Sampling Water With Electrolyte-Gated Organic Transistors Sensitised With Langmuiur-Deposited Calixarene Surface Layers., Delia Puzzovio, Abdullah Al Naim, Lee Hague, Mary Deasy, James P. Ward, Tim Richardson, Martin Grell Jan 2012

Technology Platform For Sampling Water With Electrolyte-Gated Organic Transistors Sensitised With Langmuiur-Deposited Calixarene Surface Layers., Delia Puzzovio, Abdullah Al Naim, Lee Hague, Mary Deasy, James P. Ward, Tim Richardson, Martin Grell

Articles

We demonstrate a technology platform that enables the development of new, surface-sensitised organic transistor sensors. We show that an organic semiconductor can still be gated by an electric double layer within the electrochemical window of water after the deposition of up to four Langmuir- Schäfer calixarene layers onto its surface. Since many calixarenes are known to selectively bind waterborne cations, this facilitates sensitising a conventional organic semiconductor with a physically deposited layer for specific cation recognition. When at least two Langmuir-Schäfer layers are deposited, these also block the electrochemical doping of the organic semiconductor, which otherwise competes with the field …


Temporal And Spatial Assessment Of Pahs In Water, Sediment, And Oysters As A Result Of The Deepwater Horizon Oil Spill, Meghan Christina Dailey Jan 2012

Temporal And Spatial Assessment Of Pahs In Water, Sediment, And Oysters As A Result Of The Deepwater Horizon Oil Spill, Meghan Christina Dailey

Electronic Theses and Dissertations

On April 20, 2010, BP's Deepwater Horizon oil rig exploded leaking over 200 million gallons of crude oil into the Gulf of Mexico for 84 days. Exposure to oil-associated polycyclic aromatic hydrocarbons (PAHs) in the water and sediment could severely impact the aquatic organisms inhabiting the Gulf of Mexico (i.e. developmental defects, reproductive effects, death, etc.). Therefore, water, sediment and oyster, Crassostrea virginica, samples were collected approximately bimonthly between May 26 and November 30, 2010 from multiple sites along the Gulf Coast, namely, two sites in Mobile Bay (Denton and Sand Reefs at 1 or 0.1 m above the bay …


Evaluation Of Soil Sustainability Along The Rio Grande In West Texas: Changes In Salt Loading And Organic Nutrients Due To Farming Practices, Christine L. Cox Jan 2012

Evaluation Of Soil Sustainability Along The Rio Grande In West Texas: Changes In Salt Loading And Organic Nutrients Due To Farming Practices, Christine L. Cox

Open Access Theses & Dissertations

Growing populations demand an increase in the amount of food being produced, which in turn, puts pressure on the productivity and sustainability of soils. The use of flood irrigation from the Rio Grande has greatly increased the salinity, sodicity, and enhanced leaching of nutrients in the Rio Grande Basin soils. To evaluate soil health, water and soil samples were collected from two pecan, one cotton, and one alfalfa field in western Texas. Each site was equipped with sensors to measure soil moisture, temperature, and electrical conductivity (EC), along with lysimeters at depths of 15, 30, and 60 cm to collect …


Sustainable Water Management In The University Of Texas At El Paso, Cora Martinez Jan 2012

Sustainable Water Management In The University Of Texas At El Paso, Cora Martinez

Open Access Theses & Dissertations

This thesis showed how to improve water and financial savings for UTEP and El Paso by improving water conservation and sustainability of the UTEP campus. The goals of this research were successfully accomplished by focusing in three principal objectives.

1. Analyze historical data of water consumption of the UTEP campus for the past decade.

2. Evaluate water consumption to quantify water consumption by buildings and type of use, as well as provide recommendations for water and cost savings.

3. Synthesize a water management framework within the UTEP Facilities' Geographic Information System (GIS) for long-term monitoring and evaluation


Water Mass Balances For The Rio Grande/Bravo From Fort Quitman, Texas To Foster Ranch Near Langtry, Texas: An Assessment Of Factors, Ramiro Lujan Jan 2012

Water Mass Balances For The Rio Grande/Bravo From Fort Quitman, Texas To Foster Ranch Near Langtry, Texas: An Assessment Of Factors, Ramiro Lujan

Open Access Theses & Dissertations

ABSTRACT

Water availability is declining in many regions of the planet, particularly in arid and semi-arid regions. Water bodies located in these regions, like the Rio Grande/Bravo at the U.S. - Mexico border, are subjected to high water demands. This research project makes an assessment of the spatial and temporal variability of elements intervening in the water mass balance for the section of the Rio Grande/Bravo between Fort Quitman and Langtry, Texas during the time period extending from January 1990 through December 2005. This document mentions the main Rio Grande/Bravo stakeholders from the U.S. and Mexico, and describes issues related …